Similar to cold calling. The person you're calling still doesn't know you or expect your call, but you happen to know someone who they know and like. By referral the ice is broken, and the call is warmer in temperature.
Salesperson: "I need to make a few calls, was there anyone at that networking breakfast who you think I should try?"
Friend: "Ya, try Pete Mullholland, he's the manager at Vandelay Industrial Supplies--we got along great"
Salesperson: "Finally I'm warm calling for a change"
That short time in the shower when you get an acceptable temperature having just made an adjustment but it's only for a few seconds as it will get colder/hotter very soon.
I was in such a hurry to rinse the shampoo out of my hair and eyes man that I used the Warm Window and got the hell outta there!